Re: [PATCH] net: qrtr: mhi: make it work again
From: Manivannan Sadhasivam <hidden>
Date: 2021-08-29 13:49:08
Also in:
linux-arm-msm
Hi Dmitry, On Sun, Aug 29, 2021 at 03:45:28PM +0300, Dmitry Baryshkov wrote:
The commit ce78ffa3ef16 ("net: really fix the build...") introduced two
issues into the mhi.c driver:
- use of initialized completion
- calling mhi_prepare_for_transfer twicece78ffa3ef16 got reverted in net-next: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/net/qrtr?id=9ebc2758d0bbed951511d1709be0717178ec2660 And you also need the below commit: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git/commit/?h=char-misc-next&id=0dc3ad3f859d3a65b335c861ec342d31d91e8bc8 Both commits are in linux-next so the issue should be fixed there and also in the mainline soon. Thanks, Mani
quoted hunk ↗ jump to hunk
While the first one is pretty obvious, the second one makes all devices using mhi.c to return -EINVAL during probe. Fist mhi_prepare_for_transfer() would change both channels state to ENABLED. Then when second mhi_prepare_for_transfer() would be called it would also try switching them to ENABLED again, which is forbidden by the state machine in the mhi_update_channel_state() function (see drivers/bus/mhi/core/main.c). These two issues make all drivers using qcom_mhi_qrtr (e.g. ath11k) to fail with -EINVAL. Fix them by removing first mhi_prepare_for_transfer() call and by adding the init_completion() call. Fixes: ce78ffa3ef16 ("net: really fix the build...") Signed-off-by: Dmitry Baryshkov <redacted> --- net/qrtr/mhi.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c index 1dc955ca57d3..f3f4a5fdeaf3 100644 --- a/net/qrtr/mhi.c +++ b/net/qrtr/mhi.c@@ -83,15 +83,12 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, struct qrtr_mhi_dev *qdev; int rc; - /* start channels */ - rc = mhi_prepare_for_transfer(mhi_dev, 0); - if (rc) - return rc; - qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL); if (!qdev) return -ENOMEM; + init_completion(&qdev->ready); + qdev->mhi_dev = mhi_dev; qdev->dev = &mhi_dev->dev; qdev->ep.xmit = qcom_mhi_qrtr_send;-- 2.33.0